Safety valve for fluid pressure systems



@cio M9 W52 F. @ROUSSEAU ETAL SAFETY vAEvE EOE FLUID PRESSURE SYSTEMS Filed March 13, 1947 Patented ct. i4, 1952 einen UNITE-D STATES Parser certes/ SAFETY VALVE FOR FLUH) PRESSURE SYSTEMS Fred reusseau, Schenectady, and Philip J. Brousseau, Peasleeville, N. Y.

Application March lt,

1947, Serial No. 7 34,322

1 claim. (c1. 30a-ei) This invention relates to a safety valve for liquid pressure systems of the pulsating type, for example, hydraulic brake systems vfor automobiles.

It is an object of the invention to provide a valve which will automatically shut-ofi the flow of the liquid medium from the master cylinder should a leak occur in a line leading to one of the braking units thereby permitting the remaining braking units to continue to operate.

A further object of the invention resides in providing a. safety valve having means to accelerate the closing of the valve when a leak occurs in a line so there will be a minimum loss of liquid from the system.

A still further object of the invention resides in providing means for refilling the broken line with liquid when the leak has been repaired whereby the valve is opened and the line is restored to full-operative condition.

Another object of the invention resides in providing a device of the above-mentioned character which is simple and durable in construction, eicient and reliable in operation and inexpensive to manufacture.

Other objects and advantages of the invention will be apparent during the course oi the following description.

In the accompanying drawing forming a part of this speciiication and in which like numerals are employed to designate like parts throughout the same,

Fig. 1 is a sectional view of the safety valve in open position, and,

Fig. 2 is a similar View oi the valve in closed t position.

In the drawing wherein for the purpose of illustration a preferred embodiment of the invention is shown the numeral 5 denotes generally the body of the safety valve which consists or" a block 6 of circular shape in cross seetion having a chamber 1 formed 1n its lower half closed by a screw cap 8 threaded on the body. A transverse passage 9 extends through the upper half of the block, one end of the passage being connected to a line 9' leading to the master cylinder of the fluid pressure system and its opposite end opening into the upper end o a vertical passage l0 communicating at its lower end with the chamber 1, as at Il. The passage 9 at its jointure with the passage l0 has a valve seat I2 for co-action with a needle valve i3 threaded in a bushing I4 mounted in the side oi the block. The needle valve is moved towards and from the valve seat by turning the hand wheel l5 whereby .1.

2 the flow or fluid between the passages 9 andl IB may be controlled. A central vertical passage I6 extends through the block and intersects the transverse passage 9 withits lower end communieating with the chamber v1. The bore ci the passage I6 is reduced at a. point below the transverse passage 9 to provide a valve seat I1 .for the ball valve i3 which is freely movable in the upper end of the bore. The bore is further reduced at its lower end to provide ay guideway for a valve actuating rod I9 which ismounted to reciprocate therein, the rod being `connected a-t its lower end to a ball iloat 2U disposed in the chamber 1. The passage I6 below the valve seat I1 has communication with the passage lil through a branch passage 2l. A screw plug 22 closes the upper end of the passage i6. The cap 8 has a discharge opening for connection with the line 23 leading to the braking unit not shown.

An L-shape pipe line 24 extends from the side of the body and has :communication with the upper end of the chamber 1. The outer end of the pipe line 2A communicates with an air chamber 25 closed by apertured disks 26 and 21. The pipe line 24 is normally closed by a spring seated disk valve 2B adapted to be opened when a suction is created in the pipe line by the flow of liquid from the chamber 1 thereby admitting air into the chamber to accelerate the flow of liquid therefrom. A pipe 29 leads from the air chamber 25 to the master cylinder to drain any fluid from the chamber that may be deposited therein.

To indicate to the driver when the flow of liquid to one of the braking units has been shutofi an electric signal may be provided having its circuit connected with a contact St mounted in the cap S beneath the ball float, so that when the float drops to the bottom oi the chamber 1 it Will engage the contact 3@ and close the circuit to the signal.

ln operation, the safety valve is inerpcsed in each of the lines leading 'from the master cylinder to 'the braking units. When the system is in full operation the chamber 1 is filled with liquid which raises the ball iicat 3% and valve actuating rod hi attached thereto. "Upward movement of the rod it unseats ball valve IS allowing liquid under pressure to pass from pasn sage s, through passage it and branch passage 2l into passage itt communicating with the chamber 1. From the chamber 1 the liquid is discharged into the line 23 leading to the braking unit. if a leak develops in the line to 'the braking unit, the liquid will be drained from the chamber 1 and the oat ball 20 and rod I 9 is body above said chamber, a, ball valve mounted lowered thereby permitting the ball valve I8 to in said vertical passage, a valve actuating rod been -repaired the needle valve I3 is Opened t0 10 sage through said body connected at one end to I8 and allOW the liquid t0 DaSS thlOUgh passage 15 a branch passage establishing communication I6 and branch passage 2| into passage I 0- When between the longitudinal passage and said vertithe system is restored to normal operation the @a1 passage below the ball valve.

needle valve I3 is closed. While the device has FRED BROUSSEAU,

been described in association with a hydraulic PHILIP J, BROUSSEAU, brake system for automobiles it is obvious the 20 same may be utilized in uid pressure systems REFERENCES CITED employed for other purposes' The following references are of record in the Ille of this patent:

as a preferred example of the same and that cer- 25 UNITED STATES PATENTS tain changes in the shape, size and arrangement Number Name Date of the parts may be made within the spirit of the 1,922,252 Martini Aug. 15, 1933 invention and scope of the subjoined claim. 2,008,393 Hess July 16, 1935 Having thus described our invention, we claim: 2,085,628 Brannan June 29, 1937 A safety valve for liquid pressure systems of 30 2,169,462 Grace Aug. 15, 1939 the pulsating type comprising a body having a 2,410,202 Crawford c Oct. 29. 1946 

